1. The Field of the Invention
The present invention relates to exercise treadmills. In more particular, the present invention relates to exercise treadmills having a pivoting hood assembly configured to incline a tread base of the treadmill to a grade of at least 20 percent.
2. The Relevant Technology
Exercise treadmills have long been a mainstay in the home and institutional exercise industry. Exercise treadmills provide a horizontal running surface which allows a user to perform running, walking, and other exercise routines in small and confined spaces. This can be particularly beneficial in cold climates where outdoor exercising can be difficult during winter months or in metropolitan areas where outdoor running is impractical.
Some exercise treadmills utilize an inclining tread base which can provide interest and added exercise benefits over non-inclining treadmills. By including the ability to incline, such treadmills allow a user to simulate an outdoor exercise environment in which slopes, hills, inclines, or other changes in grade are encountered. Use of an incline provides a user a with a varied exercise experience while also allowing changes in intensity and targeting of different muscle groups utilized during a workout on the treadmill.
One problem encountered with the use of inclining treadmills, is that many treadmill designs only provide a small amount of incline which can limit the interest and exercise benefits associated with exercising on an inclining tread base. For example, an exercise treadmill providing a maximum of a 10 percent incline may provide little perceptible difference in incline over a traditional horizontal tread base. Furthermore, a 10 percent incline may not effectively replicate conditions encountered during an alpine hike, a strenuous hill run, or situations encountered during other outdoors activities.
Some exercise treadmills have been developed with a greater degree of incline to provide both added interest and exercise benefits not realized with other exercise treadmills. Such inclining treadmills can incline to over a 20 percent grade. While this may provide the added interest and exercise benefits not realized in other treadmills, such treadmills nevertheless suffer from several deficiencies. To achieve greater levels of incline, such treadmills utilize design configurations that add to the cost and complexity of the design of the treadmill. Additionally, such design configurations often introduce design elements that can lead to malfunctioning of components of the treadmill. For example, some designs utilize a large and heavy frame that is contiguous with much of the length of the treadmill tread base. The large and heavy frame allows the lift motors to be positioned below the tread base to efficiently raise the tread base to the desired degree of incline. However, the weight and cost associated with such heavy and large tread base frames can substantially increase the overall cost of the treadmills. Additionally, the additional weight of the treadmills can make the treadmills difficult to transport, store, and reposition in the exercise setting. The size of the frame increases the overall footprint of the treadmill. The larger footprint of the treadmill renders the benefits of a folding tread base storage position largely unbeneficial.
Other treadmill designs utilize a lift motor design which can cause twisting of the tread base frame. For example, some treadmills utilize a dual lift motor design to provide the amount of lift required to achieve the desired grade of incline of the tread base. Twisting of the tread base often results from interaction between the lift motor(s) and the tread base. The force exerted on the tread base by the lift motor(s) can be disproportionate on different parts of the tread base resulting in twisting of the tread base. Twisting of the tread base frame can result in torsion of the endless belt on the tread base. Torsion of the endless belt can cause misalignment or derailing of the endless belt.
By utilizing a lift motor design in which the lift motor does not interact directly with the tread base, twisting of the tread base can be eliminated. One exemplary design utilizes a lift motor which interacts with the hood connected at the front of the tread base. By interacting with the hood, uneven distribution of forces is minimized and reliability of the tread base and endless belt is improved. While such designs can eliminate problems associated with twisting the tread base, the grade of incline that have been realized utilizing such designs has also been limited.